Dual oil supply pump

Abstract

An automotive engine oil pump assembly having first and second pump mechanisms contained within a common housing. A shaft rotatably supported in the housing drives the pump mechanisms in a conventional manner. The pump mechanisms are offset in phase to reduce flow pulsations through the housing and limit pump noise and vibration. The first pump mechanism communicates with a common inlet and first outlet of the housing. The second pump mechanism communicates with the common inlet and second outlet of the housing. A common reservoir connected to inlets of the first and second oil pump mechanisms provides a supplemental oil source to balance oil pressures at the pump inlets to prevent pump cavitation and further reduce pump noise and vibration.

Description

TECHNICAL FIELD [0001] This invention relates to engine oil pumps and, more particularly, to dual oil supply pumps for use in automotive lubrication applications. BACKGROUND OF THE INVENTION [0002] Dual oil supply pumps are used primarily in conjunction with industrial hydraulic applications. However, dual oil supply pumps have also been used in automotive applications. One such automotive dual oil supply pump utilizes two individual oil pumps each having a discrete housing. While this pump meets engine oil flow requirements, its packaging requires a large amount of volume. [0003] Dual oil supply pumps which are contained within a common housing to reduce packaging volume may under high flow rates experience flow imbalance between the pumps. Specifically, when one pump draws a greater volume than its counterpart does, the pump drawing the greater amount of oil can starve the other pump. Additionally, pumps contained within a common housing usually operate on the same frequency resul...

AI Technical Summary

Benefits of technology

[0004] The present invention provides an oil pump assembly having first and second pump mechanisms contained within a common housing to maximize packaging efficiency of the pump. The pump assembly also provides adequate inlet oil flow to each of the pump mechanisms to prevent flow imbalance and cavitation during operation. Furthermore, the pump mechanisms are offset in phase to reduce flow pulsations through the housing to reduce pump noise and vibration.

[0005] The pump assembly includes a housing defining an interior cavity, a common inlet, and first and second outlets. A shaft having an external drive is rotatably supported in the housing and extends through first and second pump mechanisms, which are rotatably connected with the shaft for driving the pump mechanisms in a conventional manner. The first pump mechanism communicates with the common inlet and the first outlet of the housing. The second pump mechanism communicates with the common inlet and the second outlet of the housing. A first pressure relief valve connected to receive oil from the first pump mechanism limits oil pressure to the first outlet by discharging excess oil flow to a common reservoir. A second pressure relief valve connected to receive oil from the second pump mechanism limits oil pressure to the second outlet by discharging excess oil flow to the common reservoir. The common reservoir is connected to the first and second oil pump mechanisms to provide a supplemental inlet oil source to balance pressures and flow demand at the pump inlets to prevent pump cavitation.

Problems solved by technology

While this pump meets engine oil flow requirements, its packaging requires a large amount of volume.

Dual oil supply pumps which are contained within a common housing to reduce packaging volume may under high flow rates experience flow imbalance between the pumps.

Specifically, when one pump draws a greater volume than its counterpart does, the pump drawing the greater amount of oil can starve the other pump.

Additionally, pumps contained within a common housing usually operate on the same frequency resulting in flow pulsations that are translated to pressure fluctuations though the pump, which may cause undesirable pump vibration and noise.

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